Video of NY pipe bomb explosion released

A newly released video shows dramatic police response in the Port Authority subway last year when a suicide bomber detonated his explosive device.

Surveillance video shows an ordinary morning rush hour crowd in December suddenly stunned by a bomb blast. Commuters took off running in both directions around a Bangladeshi immigrant, emptying the corridor within seconds.

Investigators say Akayed Ullah was living in Brooklyn when he allegedly committed this act of terrorism.

Ullah told police he made the crude pipe bomb from materials he bought and found. When the smoke cleared, Ullah lay on the ground for quite some time before police cautiously swarm him.

Once they realized he had explosives strapped to his body, they followed their training and retreated as quickly as they descended on him.

All the while, never reaching for their radios or any electronics that could trigger a bomb. Ullah's right leg twitched every so often, but for most of the time, he stayed spread eagle, on the ground severely injured.

It turns out the "low-tech" pipe bomb did not fully explode. Prosecutors have said Ullah wanted to cause carnage to avenge U.S. aggression toward the Islamic State Group.

Ullah has pleaded not guilty to terror charges, including providing material support to a terrorist organization and using a weapon of mass destruction.